Control of electrically-operated switches.



A. S.- CBITT. CONTROL OP ELEGTRIGALLY-OPBRATBD SWITCHES". APPLIOATI'ON FILED Mmm 1908.

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Patented Nov. 3o, 1909. l

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4 Aps. CUBIT'I'.v A CONTROL 0F ELEGTRICALLYUPERATED SWITGHBS.-

' 'APPLICATION FILED M'AY 7, 1908.`

941,408. `v Paentedv Nov. 30,1909. l 2 SHEETS-SHEET 2.

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UNrrED fsTA'rns PATENT OFFICE. y

ARCHIBALD S. CUBITT, OF SCHENECTADY, VNEIN YORK, ASSIGNOR TO GENERAL ELC- TRIO COMPANY, A CORPORATION OF NEW YORK. l

CONTROL OF yE.LEC'IIRICALLY-OPE,RATED SWITCHES.

Specification of. Letters Patent.

Patented Nov. 3o, 1909.A

Application meu may 7,1503." seria1No.431,442. y

To all 'whom it may concern.'

Be it known that I, ARCHIBALD S. CUnrTr, a subject of the King of Great Britain, residing at Schenectady, in the' countyv of Schenectady, State of N ewYork, have invented certain new and useful lImprovements in the Control of Electrically-Operated Switches, of which the following 1s a specification.

My invention relates to the operation of electrically controlled'switches and particu- Vlarly to the-operationA successively in a certain order of a plurality of such.switches.

It is especially useful 1n connection with systems of motor control in .which a plurality of electrically controlled switches are arranged to operate in succession to increase step-by-step the voltage or current applied to the motor. Arrangements of this kind are employed in the starting of electric Inotors and have been s'o arranged that by closing a single switch the electrically controlled switches arecaused'to operate automatically in succession 4to cut out section-by-section resistance interposed in themotor circuit on starting, or in some other Way to increase step-by-sten the voltage or current appliedv l to the motor. Such arrangements havevalso been used insystems of motor control in which a master switch serves to regulate theoperation of 4the series of electrically controlled switches, .the arrangement being ysuch that the master switch may either directly control the operation of the switches one at a time ormay cause any lnumber or all of them to operate automatically in succession.

In such systems. o'fmotor control'itis desirable v that` a certain time interval, the length of-which depends upon the condi- `tions'of service, should elapse between the operation of successive switches. To this end diilerent arrangements havebeen employed. It is also often desirable thaty they successive operation of. the` switches beretarde'd itat any time the current ln ,the 'motor circuit exceedsa-`certain value, due to closing of the `switches too rapidly. Va-

- rious systems have been used for givingthis above described purposesfone of` the best so-called time and current limit to thev action l'of a series of switchesused for the known arrangements4 being ythe luse of 'a notching relay whlch serves-to-interrupt the actuating circuit for the series of. 'switches after each switch hasoperated and to maintain said circuit interrupted-'as long as the motor current exceeds a certain value. It is an object of my invention to provide Aan improved system of control for al plu- To this end I use, 1n connection with a series of electrically controlled switches, a plurality of actuating circuits connected suc` cessively to successive switches and provide means vcontrolled by 'current through Asaid actuating circuits cooperating with means controlled bythe switches themselves for causing energization of said actuating circuits successively.

.I have shown my invention as applied to a simple system of `control for a direct current motor, but this is merely illustrative and, as will be lobvious to those skilled in this art, lit may equally Well be applied to the control .of other forms of dynamo-electric machinery and toother t pes of control such, for example, as the Wel-known seriesparallel method used extensively in the con' trol ofl electrically driven cars.

Referring to the drawings, Figure l illustrates diagrammatically a system of motor controlv having-my invention embodied therein; Fig. 2 is a View of a portionof a system `similar to that shownlin Fig. l but with a different form of'relaymechanism applied` thereto' Fig. 3 is a front elevation of a relay of the orm shown diagrammatically inFig. 2; andFig. 4` is a side elevation, partly in section, of the relayshown in Fig. 3.

Referring to Fig. l, at M is indicatedA the motorto be controlled. R1 to R are a plurality vof resistances arranged. to be interosed in the motor'circuit in starting and to e short-circuited, respectively, bythe electrically controlled switches of contactors 1` to 100 6 which may be of any well-known and suity able form.;4 A source of current supply is indicated at L, the other sidef-of the source ybeing ground.4 A line switch Zwhen. closed Vserves to connect the motor' tothe source 105 through the resistances R1 to R". A master switch .K, shown diagramniaticall in Ika .usual manner, may be offany wel -known form, Such as a drum controller having segments 7, 8, 9, l0 'and 11' which engage respec-z 110 l lingers 7', 8", Ei', 10 and 11". 7 is connected to the source.

tively with ,lhe finger "The linger 8 is connected to a wire 12 which- 2, f1 and 6. The wire 15 is connected in series with the actuating coil of a relay 0 and .has interposed vtherein contacts closed by vtherelay O when the same is denergized. Similarly, the wire 16 is connected in series with the actuating coil o 'of the relay O and in series with the contacts'of the relay O. These relays O vand O 4ma;y-,be..-of any well-known and simple form and may be provided respectively with heavy coils P and P .of few turns arranged in series with the motor circuit as shown. These relays are arranged to pull up on energization of f the coils 0 and 0, and to be held up by the magnetizing effect of the coils P and P if' the current through these coils exceeds a certain value. Relays for operation in 'this way are well-known and need not bedescribed in detail. to a wire 17 which serves as a return for the actuating coils of the line switch Z and the resistance controlling switches 1 to 6 inclu sive, Finger: 11 is connected to ground. Segments 7, v8 and 9 'a'.re electrically conswitches 1 to G inclusiv@I operate auxiliary switches ofany well-known form, those illustrated being of the type in which contact disks, carried by a rod moved by the owing description of the operation of they i system. l.

`The operation of the system of control v illustrated is as follcws:The master switch K being turned to its` irstppsition m current 'passes fronithe source L to the .finger 7',

7 and through segments 7 and 8 to finger 8,

i through the wire 12 to and through thev actuating coilof the line switch Z, through wire 17 to the finger 10,a,nd'tl1rough seg- Y which, as-statcd above, is the other l"side of the source. The Aline switch Z will close, -tl'1erefore,. and* the motor circuit .will be com- .pleted fronir'the source L, through the resistances -ItlgtoltG and the motor M to circuits for switches 1, 3 and 5 and switches `Finger 10 is connected.

nected as are also segments 10 and 11. The

aplparent from the drawing ,and from the fo l l' extent, dependent upon `the rate a1;-

ients 10 and 11 Aand finger 11 to groundv ground. As 'long' as'the master switch remains in vthis position no further change inthe -circuits will take place. If, however, the switch K'is turned to its second position y, the linger 9.. will engage with segment 9 7c yand current will pass` from the source L, through. finger 7', se ment 7, .segment 9, to finger 9, through wire 13, actuating coil `0 of the relay O, contacts of relay O wire 15, through the auxiliary switch a,1 of the switch 1 and through 'the actuating coil of this switch to ground through the wire 17. The switch 1 will, therefore, close and in closing will close the auxiliary switch b1 which will, complete a maintaining circuit for the switch 1 from the maintaining wire12, after which the auxiliary switch alwill beolened and the auxiliary switch c1 will be closed. The current passing through the wire 15, even before, causing the switch 1 to close, will ,cause the core of relay O to pullup thereby interrupting the circuit through the 'wire 16. Vl7hen,- therefore, .`the auxiliary switch c1 closes, although it will complete a circuit v6 through the auxiliary 'from the wire '1 90. switchfa2 on switch 2 to the actuating coil ofswitch2, this coil will not Vbe energized while the contacts of the relay O are open. Closing of the switch 1, however, has, by opening the auxiliary switch u1, interrupted the circuit through the wire 15 and the actuating coil o of the relay O and the core of this rela-y will, therefore, be free to drop' l unless it is heldin its raised position by the magnetizing effect of the coil P. As above stated, the relays Oand O are so desi ned open only if the motor current exceeds fa certain value.V If, therefore, the short-cir'- cuiting. of the section of resistance R1 increases the current flowing in the motor cir-. cuit suliicientlyto holdup the relay O, the' 'completion of .the .circuit through the wire.

motive force of the motor has out clown thev current iowing inthe motor circuit. The;f -f' closing ofthe switch 2, therefore, carino Atake, place until a certain time interval ha elapsed after the closing of 'switch 1-. .Tl time'inter'valvwill have a certain mininrixu h the cores of the relays `O .and O d op an will be `increased if theA current inth circuit rises to `a value sufficient toni holding coils `P andP operative.4 ping of' the vrelay OV a circuit will* pleted lfrom the wire 13,'throughfthegcoito of the relay through contactsofrrelayft), j through wire 16, through.auxiliaryvswitcli c1, auxiliary f switch a and actuating il-o switch 2 to ground through'the` w e417. The relay Owill, therefore, ull up and the switch k2 wil close.v Switcii 2 in `closing closes uuxliaryswi'tch Z1?, opens auxiliary switch -a and closes-'auxiliary' switch c2.

that the coils P and P will hold there ays 16 will be-retarded until the counter electro"- ...The actuating coil Aof switch 2 is, therefore,

connected to the maintaining wire 12 and the actuating coil of the switch 3 is connected tothe wire 15 and will close as soon asV the relay0 has dropped. In this way the closing of the switches 1 to 6 inclusive will take place'l automatically in succession under the control of the relays 1) and O, an 'interval of time being insured between the closing of said switches, this interval being dependent upon the value of the currents passing in the motor circuit. The successive operatlon may, of course, be stopped at any :time and the switches Whichhave closed held in that position, *by* throwing the masterswitch 'K back to its first position w.

`Instead of the relays O and O of Fig. 1'v

a relay O2, shown'diagrammatically in Fig. 2 and in detail in Figs. 3V and 4, may be employed. Referringto Figs. 2, 3 and 4 the relay O2 comprises a frame 19 .which may be secured in any suitable manner, as; by bolts 20, to a base-board 21 preferably of insulating material, within which lframe are arrangedY an ac tuatingcoil of small wire and a holdingcoil ,23 of heavy conductor.

Arranged for move'mentwithin the coil2'2.

is a core 24 of magnetic'fmaterial from the bottom 4of Ywhich extends a rod 25 yupon collar and the collarv-3 which arelmounted thefjmovable contact Vmembers of thel relay. ;Afixed core 26 is secured to the framev 19''and projects down-l wardlyawithin the coils'23and 22, as shown in Fig.` 4.v` rodf27 may extendl upward from the movable `core 24 through a hole in the fixed core 264 and byengaging with an adjustable serew 2 8 will serve as a stop for the core 24f, in'vitsupwa rd` movement. A brass washer -29 vmay 'be 'placed 4above the core 24to prevent sticking of this core to the fixed core-26 in a manner well understood. These parts ofy the`l relay may be of any well-known andjv suitable design.' Uponthe rod 25 are slidingly mounted a plurality of steel contact disks 30 andl 31. The disk 31 is yieldingly held -by means of a coil spring 32 'against the collarl 33 mounted 'upon the rod 25, the lower end'of the sprin 32 abutting ,against the.. collar 34 also fixed which rests upon the -collar 33, the up er side oflthis disk4 bein engaged Aby a ,col ar 36 which has a limite movement .on-'the rod 25,' this being provided, for example,` by means` of a pm 37 which-pas`ss through a slot in the rod 25.'. Ongtherod=25 above the collar 36 is fixed a collar 3Sfvand between this 39 as shown, The---gisy 0- engages with fixed contacts 41'I and 42 @of magnetic material whichl are secredto thel base. plate 21 andr are surrounded= by-ff'ma ycth/.ing coils 43 and 44 which lare connectedns'eries'with vthecontacts 41 and 42-A andserv'ewhen cur- 'iiterposed 'a spring' mnt passs through these contacts tq-'holdf magneticallythe disk 30 in engagement with the contacts 41-and 42 while` the .core 24 rises to its. full extent. Similarly, the disk 31 engages with fixed contacts 45 and 46 of magnetic material surrounded by magnet1z ingfcoils 47 and 48 connected in series with to prevent sticking of the disks to thefcontacts after the magnetizing coils are ldenergized and to insure good electrical connection 'at these points, this expedient being well-known in this art. The slight yieldingI connection between' the collar 36 and the rod 25 insures both disks,30 and 31 being held in close engagement with their coperating contacts -when'the relay is down, in amannerv obvious from the drawing. When this form of relay is employed, as will be clear from Fig. 2,the wire 13, of Fig. 1, is connected in series .with the actuating coil 22 ofthe relay-O2 and at 14 branches into two circuits which pass through the upper and lowercontacts of the relay andconnect to the two-Wires l5 and 16. A

The operation of the system of control shownvin F ig. 2, when provided with the form of relay illustrated in 2,3 and 4, is the same as far as the operation of the line switch Z and the lresistance contro1ling' switches 1 to 6 inclusive .is concerned.

lVhen the master switch K is turnedY toits first position .fr the line switchl is closed, as described above. Upon turning the master switch K to' its position y the circuit through the wire 13 is completed yand the wire 15,

leading to ,the loperatin coil of switch 1, is

31, however, is magnetically held in engage- `I men't with its contacts until the interruption of the current through the wirejl, due to the' closing of the switch 1 andthe opening of the auxiliary switch a?, after which the. disk 31 snaps upwardly under'the influence of the spring 32. If thel closing of switchl 1 has resulted in increasing the'motorcurrent sufliciently to render the holding coil '23 Aon the relay eec'tive, the core of the relay willbe held in, its raised position and the circuit through the', wire 16 will beV maintained interrupted, thereby preventing the operation of the switch 2. When the motor current has decreased sufficiently by the increasing counter-electromotive force of the motor, the core of the relay O2 drops andthe circuit through thewre 16 is completed thereby ot' the relay O2 rises, the disk 30l being this `time held in engagement with, its contacts while the disk 3].'l is lifted.- In' this manner the relay()2 acts-'exactly as do #relays O and to control the alternatev energization of` ally controlled switches, a plurality of acthe' wires 15 andilti.l lt;

iVhile I haveshown" my invention asembodied in a system of control-"in which there are but two actuating circuits."I do not wish to be understood as limiting'itto such systems since it might equally well be carrled out in Vconnection with systems having a greater number of actuating' circuits, as will be obvious to those skilled in this art.

`What lI lclaim as new and desire to securel by Letters Patent of the United States, is:

l. In combination, a plurality of electriclally controlled switches, a plurality of actuating circuits connected successively to successive. switches, and means normally closing contacts in all of the actuatingcircuits and controlled. by current through any actuating circuit for temporarily interrupting the suc' ceeding actuating circuit.

2.111 c'omblnation, a 'plurality of electrically controlled switches, a plurality of actuating circuits connected successively toysuccessive switches, means controlled by current through any actuating circuit for tem-- porarily interrupting thevsucceeding actua t'l ing circuit, and means, controlled by the several switches for connectingv the succeeding switch to its actuating circuit. 8. In combination, a plurality of electrically controlled switches, a plurality ofactuating .circuits connected successively to suc-I cessive switches, means controlled yby current through any actuating circuit for tem- Iporarily interru ting the succeeding actuating circuit, an means 'operated by each switch in closing for vopening its actuatingl circuit.

. 4. In combination, a plurality of electric ally controlledswitchs, a plurality of actuating circuits connected successively to suc- -cessive switches, an auxiliary switcli closed by each switch except the last in closing or completing the actuating c1rcu1t for the suo ceedlng switch, and means operated by curl: vrent through any'actuatlng clrcuit fortem-y Uporarlly interrupting the` lactuating circuit for the succeeding switch before 'said auxiliary switch of the preceding switch has closed.

. 5. In combination, a plurality of electrically controlled switches, a` plurality. of actuating circuits connected successively to successive switches, an auxiliaryv switch con# trolled by' each of said first named switches for controlling the actuating 4circuit tor that switch, an auxiliary switch closed/by each switch except the last in closing tor complet-ing thcacthating circuit for the sue- .auxiliary switch in -that circuit operated van., -vv

ceeding switch, andv means operated by cur# rent through any actuating .circuit for temporarily opening contacts in the actuating.- circuit, for the succeeding switch before the 'zo the preceding switch has closed.

6. In comblnatlon, a plurahty of electrictuating `circuitsconnected successively to successive switches, auxiliary switches controlled by each of said first named .switches for completing a holding circuit :tor that switch and forv disconnecting said switch from its actuating circuit,` an auxiliary switch closed byeach switch vexcept the last in closing for connecting the succeeding switch to its actuating circuit, and a relay mechanism operated by current through any actuating circuit for opening contacts in the .succeeding actuating circuit, said mechanism-when, in its norma1'-position being arranged to close contacts in 'all the-actuating circuits.r i

7. In combination, a plurality of electrically controlled switches, a plurality of actuating circuits connected successively to successive switches, a plurality of relays the 'actuating coils of which are each connected in an actuating circuit through contacts opened by the relay in the preceding actuat-`ring circuit when energized, 'auxiliary switches `controlledby each of said first 'named switches for interrupt-ing the connec- "tion'between that'switch and its actuating circuit after said switch has.. operated, and 1,00 an auxiliary switch controlled by each of said irst named switches except the lastor connecting the succeeding switch toits actuating circuit.

8; In combinatioma pluralityof electric- 105 "ally controlled switches, two actua-ting circuits arranged to control alternate switches, and means automatically controlled by the current' through lsaid actuating circuits `for l causing cnergiaation of said actuating circuits alternately.

9. In combination, a plurality oit electrically' controlled switches, two 'actuating circuits arranged to control alternate switches, and electro-magnetically operated means automa-tically controlled by the current through said actuating circuits for causing energization of said actuating circuits.alternately.

10. In'combination, a plurality of electrically controlled switches.v two actuating circuits arranged to control` alternate switches,

means controlled by current through said actuating circuits for automatically causing` energization 'of said actuating circuits alternately, and switches operated by said electrically controlled switches for assuring the closing of .said last. named switches in regular order.

l1. In combination, a pluraiity ot' electrically controlled `swilchcstwo actuating 'cir- 130 1Q. In combination, a plurality of electricf' ally controlled switches, two actuating circuits connected to. alternate switches, means controlled by current through said actuating circuits for automatically causing temporary energization of said circuits alternately, and means controlled by each switch for com -pleting a maintaining circuit `for itself and for connecting the succeedingswitch to one of the actuating circuitsfr 13. In combination, a plurality of electric' ally controlled switches, twoiactuatingcir cuits connected to alternate switches, means automatically operated by current/through either actuating circuit for opening contacts vin -the other actuating circuit, and means operaled by eaclrs'witch in closing for disconnecting its actuating coil from its actuating circuit.

141-.' In combination, a plurality of electrically controlled switches, two actuating cir.

cuits connected to alternate switches, auxiliary switches controlled by each of Said first named switches lfor completinga holding.

circuit for that particular switch and for disconnecting the switch from its actuating circuit, an auxiliary switch closed by `each switch except the last in closing for connecting lthe succeeding switch to itsactu'ating .circuit, and rela-y vmechanism operated by current through either actua-'ting circuit for opening contacts inthe other actuating circuit, said mechanism -when in its normal position being arranged to close contacts in both actuating circuits. y,

\ 15. In combination, aplurality of electrically controlled switches, two actuating circuits leading to alternate switches, two relays the actuating coils of which are each i connected in an actuatingpcircuit through contacts opened by the other relay when en; ergized, auxiliary switches controlled .by each of said first named switches for interrupting the connection between the switch and its actuating circuit after said switch has operated, and an auxiliary switch on cachotl said rst named switchesl except the last for connecting the succeeding switch to its actuating circuit. A

1 6.; In combination, a plurality of contactors intended for operation in succession, a source of current, a switch opened by each contactor in closing located in the actuating circuit from said source to that contactor,'a switch `closed bypveach contactor except the last .in closing located in the actuating circuit from the source to ther succeeding conlactor, and means electrically controlledby current in the actuating circuit to each contactor except the last for temporarily interrupting the actuating circuit from said source .to the succeeding contactor withouty interrupting the actuating circuit to the contacter about to close.

17. In con'ibination, a plurality of cont-actl ors vintended for-operation in succession, a source of current, a switch opened by each contacter in'V closing located in the actuating circuitfrom said source to thatcontactor, a switch closed by each switch except the lastin closing located in the actuating circuit from the source to the succeeding contactor, and means-electrically operated by current in the actuating circuit to` each` contactor except the last forinterruptingand maintaining vvinterrupted the actuating circuit to the succeeding contacter while the actuating circuit of the j contactor preceding itis receiving current through the 4lirst named switch.4 j

In witness whereof, I have hereunto set 4my hand this 6th day of May, 1908.

ARCHIBALD S. CUBITT. 

